HIGHLANDS RANCH | Douglas County authorities say police were justified in shooting a gunman after he killed a Highlands Ranch deputy and wounded four other officers late last year.

Deputy District Attorney Jason Siers says Matthew Riehl posed a “deadly threat” to officers who responded to the shooting.

According to police, Riehl called 911 twice early on Dec. 31. When deputies on the second call came into the apartment to take Riehl into custody on a mental health hold, he opened fire from behind a bedroom door.

In a letter released Monday, Siers wrote that Riehl continued to shoot at SWAT team members who came to retrieve the slain deputy. He found the officers who fatally shot Riehl were defending themselves and others.

The letter says Riehl also wounded two neighbors as he exchanged gunfire with police.